Tính nhanh
a) 452+332-222+90.33
b) 1112-1372-48+96.1382
Những câu hỏi liên quan
Tính nhanh: 45 2 + 33 2 − 22 2 + 90.33
Tính nhanh:
a) 41.24-41.14+59.24-59.14
b) 452+332-222+90.33
a) \(41\cdot24-41\cdot14+59\cdot24-59\cdot14\)
\(=41\cdot10+59\cdot10\)
\(=1000\)
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Bài 3: Tính nhanh:
a) 2,83.5,68-2,83.4,68+1,17.5,68-1,17.4,68
b) 1112-1372-482+96.137
a) 2,83.5,68-2,83.4,68+1,17.5,68-1,17.4,68
= 2,83.(5,86-4,86)+1,17.(5,86-4,86)=2,83.1+1,17.1=4
b) 1112-1372-482+96.137
= 1112-(1372-2.48.137+482)=1112-(137-48)2=1112-892=(111-89)(111+89)=22.200=4400
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a) 2,83.5,68-2,83.4,68+1,17.5,68-1,17.4,68
= (2,83.5,68-2,83.4,68)+(1,17.5,68-1,17.4,68)
=2,83.(5,68-4,68)+1,17(5,68-4,68)=2,83+1,17=4
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a: Ta có: \(2.83+5.68-2.83\cdot4.68+1.17\cdot5.68-1.17\cdot4.68\)
\(=2.83\left(5.68-4.68\right)+1.17\left(5.68-4.68\right)\)
\(=2.83+1.17=4\)
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Tính Nhanh
a) 78 . 82
b) 452 + 552 + 90.55
a: \(78\cdot82=80^2-4=6400-4=6396\)
b: \(45^2+90\cdot55+55^2=100^2=10000\)
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Bài 5: Tính nhanh
A, 327 - 16 + 216 - 27 + 600
B, 16 x 48 + 8 x 48 + 16 x 28
giúp với 
327 - 16 + 216 - 27 + 600 16 x 48 + 8 x 48 + 16 x 28
=(327 - 27) + (216 - 16) + 600 =16 x 48 + 16 x 24 + 16 x 28
=300 + 200 + 600 =16 x (48 + 24 + 28)
=500 + 600 =16 x 100
=1100 =1600
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Tính nhanh
A=1+\(\dfrac{1}{8}+\dfrac{1}{24}+\dfrac{1}{48}+\dfrac{1}{80}+\dfrac{1}{120}\)
Ta có: \(A=1+\dfrac{1}{8}+\dfrac{1}{24}+\dfrac{1}{48}+\dfrac{1}{80}+\dfrac{1}{120}\)
\(\Leftrightarrow2A=2+\dfrac{2}{2\cdot4}+\dfrac{2}{4\cdot6}+\dfrac{2}{6\cdot8}+\dfrac{2}{8\cdot10}+\dfrac{2}{10\cdot12}\)
\(\Leftrightarrow2A=2+\dfrac{1}{2}-\dfrac{1}{4}+\dfrac{1}{4}-\dfrac{1}{6}+\dfrac{1}{6}-\dfrac{1}{8}+\dfrac{1}{8}-\dfrac{1}{10}+\dfrac{1}{10}-\dfrac{1}{12}\)
\(\Leftrightarrow2A=2+\dfrac{1}{2}-\dfrac{1}{12}\)
\(\Leftrightarrow2A=\dfrac{24}{12}+\dfrac{6}{12}-\dfrac{1}{12}\)
\(\Leftrightarrow2A=\dfrac{29}{12}\)
hay \(A=\dfrac{29}{24}\)
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Đặt tính rồi tính:
48 + 26
90 − 32
452 + 216
976 − 345
2. Tinh nhanha) 342 : 2+ 436 : 2 + 222 : 2b) 875 : 5 –125 : 5 –250 : 5.....................................................................................................c) 3456 : 3-456 : 3 –99 : 3...........................................d) 2980 : 10 + 3570 : 10 –1580 : 10-1970 : 10.....................................................................................................................................................................................ai giúp mình đầu tiên thì mình ti...
Đọc tiếp
2. Tinh nhanh
a) 342 : 2+ 436 : 2 + 222 : 2
b) 875 : 5 –125 : 5 –250 : 5.....................................................................................................
c) 3456 : 3-456 : 3 –99 : 3...........................................
d) 2980 : 10 + 3570 : 10 –1580 : 10-1970 : 10......................................................................
...............................................................................................................
ai giúp mình đầu tiên thì mình tick nha
bài 7:tính nhanh
a (145 x 99+145)-(143 x 102-143) b,54 x 47 - 47 x 53 - 20 -27
c, 10000 - 47 x 72 - 47 x 28 d, 3457 - 27 x 48 - 48 x 73 + 6543
a) \(\left(145\times99+145\right)-\left(143\times102-143\right)\)
\(=\left[145\times\left(99+1\right)\right]-\left[143\times\left(102-1\right)\right]\)
\(=\left(145\times100\right)-\left(143\times101\right)\)
\(=14500-14443\)
\(=57\)
b) \(54\times47-47\times53-20-27\)
\(=47\times\left(54-53\right)-20-27\)
\(=47-20-27\)
\(=0\)
c) \(10000-47\times72-47\times28\)
\(=10000-47\times\left(72+28\right)\)
\(=10000-47\times100\)
\(=10000-4700\)
\(=5300\)
d) \(3457-27\times48-48\times73+6543\)
\(=\left(3457+6543\right)-48\times\left(27+73\right)\)
\(=10000-48\times100\)
\(=10000-4800\)
\(=5200\)
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